The present invention relates generally to vehicle seating and more specifically, to a recliner mechanism for use in connection with reclining a vehicle seat.
Many vehicle seats have a recliner mechanism so that a seat occupant may selectively adjust a seatback relative to the seatbase to provide different positions depending on the desired position of the occupant. The recliner mechanism may be a powered recline mechanism or a manual recliner mechanism. The present invention generally relates to a manual recliner mechanism. Most manual recliner mechanisms are puck-shaped, internally-toothed and use an internal cam mechanism to selectively lock and release the seatback relative to the seatbase.
Recliner mechanisms generally include a seatbase bracket, coupled to the seatbase to securely retain the mechanism. A base plate is typically affixed to the seatbase or seatbase bracket and the top plate is typically affixed to the seatback. Secure welds or other fastening techniques are used to secure the base plate to the seatbase or seatbase bracket and the top plate to the seatback.
The recliner mechanisms typically further include at least one pawl member having teeth that are engaged with teeth on the top plate, when the recliner mechanism and therefore the seatback is locked from rotational movement and disengaged from the top plate when the recliner mechanism and therefore the seatback is capable of rotational movement.
In operation, a typical rotary recliner mechanism is spring biased to a locked condition, i.e., so the seatback is fixed in an angular position until pawls are intentionally disengaged from the top plate. More specifically, when the recliner mechanism is actuated, typically by a handle or lever rotating the driveshaft, the cam member rotates to release the pawl members from engagement and indirectly through use of a guide plate, moves the pawl members inward thereby removing the teeth of the pawl members from the teeth of the top and plate thereby unlocking (or releasing) the recliner mechanism, such that the seatback may be selectively pivoted in the fore or aft direction to adjust the vehicle seat.
Such rotary recliner mechanisms are carefully designed to meet current safety requirements while also limiting the amount of slack or play that can be perceived by a seat occupant. As a result, prior art recliner mechanisms tend to be heavily constructed items in order to withstand certain load conditions and as such, add significantly to the overall vehicle weight. For example, in order to withstand radial stresses caused when the pawl member teeth are engaged with the internal teeth of the top plate, the base plate and the top plate are typically formed with a large material thickness which adds weight.
Further, since the release handle is used often by the occupant, the pivot and cam can be subject to high forces which may ultimately cause play in the interaction between the release handle and the recliner mechanism. Rotary recliner mechanisms are also time consuming to assemble.
There remains a significant and continuing need to provide an improved recliner mechanism that can handle greater loads, weigh less and reduce play between the release handle and the recliner mechanism, and are easy to assemble.